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Klaus
Klaus

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Selenium Cheat Sheet

#testing #webdev #javascript

Selenium is a framework for testing web applications.

Below is my cheat sheet for Selenium.

I'm using Python 🐍, but the concepts are the same for the rest of the languages.

I use Endtest to quickly create Automated Tests and execute them on the cross-browser cloud.

You should check out the docs.

1. Import the Selenium library

You can get Selenium from here.

from selenium import webdriver
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2. Start the webdriver and the browser

Starting the webdriver and the Chrome browser.

You can get ChromeDriver from here.

chromedriver = "C:/tests/chromedriver.exe"
driver = webdriver.Chrome(executable_path = chromedriver)
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Starting the webdriver and the Firefox browser.

You can get GeckoDriver from here.

geckodriver = "C:/tests/geckodriver.exe"
driver = webdriver.Firefox(executable_path = geckodriver)
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Starting the webdriver and the Internet Explorer browser.

You can get IEDriverServer from here.

iedriver = "C:/tests/IEDriverServer.exe"
driver = webdriver.Firefox(executable_path = iedriver)
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Starting the webdriver and the Safari browser.

Nothing to download. The SafariDriver is integrated in Safari.

driver = webdriver.Safari()
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Instead of having machines with all those browsers, I just use Endtest.

It's a platform for Codeless Automated Testing where you can create, manage and execute tests on real browsers on Windows and macOS machines and mobile devices.

3. Open a website 

the_url = "https://example.com"
driver.get(the_url)
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4. Find an element

Let's try to find this element:

<a href="/sign-up" id="register" name="register" class="cta nav-link">Sign Up</a>
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Find element by ID 

the_id = 'register'
element = driver.find_element_by_id(the_id)
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Find element by Name 

the_name = 'register'
element = driver.find_element_by_id(the_name)
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Find element by Class Name 

the_class_name = 'nav-link'
element = driver.find_element_by_class_name(the_class_name)
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Find element by Tag Name 

the_tag_name = 'a'
element = driver.find_element_by_tag_name(the_tag_name)
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Find element by Link Text

Works only for anchor elements.

the_link_text = 'Sign Up'
element = driver.find_element_by_link_text(the_link_text)
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Find element by Partial Link Text

Works only for anchor elements.

the_partial_link_text = 'Sign'
element = driver.find_element_by_partial_link_text(the_partial_link_text)
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Find element by CSS Selector

You can extract the CSS Selector from the browser.

Or you can write your own by using an attribute from the element:

*[attribute="attribute_value"]
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For our element, a custom CSS Selector would be:

a[href="/sign-up"]
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the_css_selector = 'a[href="/sign-up"]'
element = driver.find_element_by_css_selector(the_css_selector)
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Find element by XPath

You can extract the XPath from the browser.

Or you can write your own by using an attribute from the element:

//*[@attribute = "attribute_value"]
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For our element, a custom XPath would be:

//a[@href = "/sign-up"]
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You can read more about that here.

the_xpath = '//a[@href = "/sign-up"]'
element = driver.find_element_by_xpath(the_xpath)
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5. Click on an element 

the_id = 'register'
element = driver.find_element_by_id(the_id)
element.click()
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6. Write text inside an element

Works only for inputs and textareas.

the_id = 'email'
the_email = 'klaus@werner.de'
element = driver.find_element_by_id(the_id)
element.send_keys(the_email)
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7. Select an option

Works only for select elements.

<select id="country">
<option value="US">United States</option>
<option value="CA">Canada</option>
<option value="MX">Mexico</option>
</select>
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Let's select Canada. 🇨🇦

You can use the visible text: 

the_id = 'country'
element = driver.find_element_by_id(the_id)
select_element = Select(element)
select_element.select_by_visible_text('Canada')
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You can use the value: 

the_id = 'country'
element = driver.find_element_by_id(the_id)
select_element = Select(element)
select_element.select_by_value('CA')
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You can also use the index: 

the_id = 'country'
element = driver.find_element_by_id(the_id)
select_element = Select(element)
select_element.select_by_index(1)
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8. Take a screenshot 

the_path = 'C:/tests/screenshots/1.png'
driver.save_screenshot(the_path)
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Selenium does not offer Screenshot Comparison but we know who does.

9. Upload a file

This works by using the send_keys method to write the local path of the file in the input type="file" element.

Let's use this example:

<input type="file" multiple="" id="upload_button">
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the_file_path = 'C:/tests/files/example.pdf'
the_id = 'upload_button'
element = driver.find_element_by_id(the_id)
element.send_keys(the_file_path)
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You can read more about uploading files in a test here.

10. Execute JavaScript

In some cases, you might need to execute some JavaScript code.

This works exactly like you would execute it in your browser console.

js_code = 'document.getElementById("pop-up").remove()'
driver = execute_script(js_code)
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11. Switch to iframe 

<iframe id="payment_section">
   <input id="card_number">
   <input id="card_name">
   <input id="expiration_date">
   <input id="cvv">
</iframe>
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the_iframe_id = 'payment_section'
the_element_id = 'card_number'
the_iframe = driver.find_element_by_id(the_iframe_id)
driver.switch_to.frame(the_iframe)
element = driver.find_element_by_id(the_element_id)
element.send_keys('41111111111111')
driver.switch_to.default_content()
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Endtest also supports iframes and it even supports Shadow DOM.

12. Switch to the next tab

You have to store the handle of your current tab in a global variable.

If you have only one tab open, the handle is 0.

global nextTab
global currentTab
nextTab = currentTab + 1
driver.switch_to_window(driver.window_handles[nextTab])
currentTab = currentTab + 1
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13. Switch to the previous tab 

global previousTab
global currentTab
previousTab = currentTab - 1
driver.switch_to_window(driver.window_handles[previousTab])
currentTab = currentTab - 1
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14. Close tab 

driver.close()
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15. Close alert 

driver.switch_to.alert.accept()
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16. Refresh 

driver.refresh()
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17. Hover 

the_id = "register"
the_element = driver.find_element_by_id(the_id)
hover = ActionChains(driver).move_to_element(the_element)
hover.perform()
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18. Right Click 

the_id = "register"
the_element = driver.find_element_by_id(the_id)
right_click = ActionChains(driver).context_click(the_element)
right_click.perform()
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19. Click with offset

In order to precisely click on a certain position in a canvas element, you have to provide the offset.

The offset represents the number of pixels to the right and down, starting from the top left corner of your canvas element.

the_id = "register"
the_element = driver.find_element_by_id(the_id)
x = 30
y = 20
offset = ActionChains(driver).move_to_element_with_offset(the_element,x,y)
offset.click()
offset.perform()
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You can read how to do this with Endtest here.

20. Press Key 

the_id = 'register'
element = driver.find_element_by_id(the_id)
element.send_keys(Keys.RETURN)
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21. Drag and drop 

element_to_drag_id = 'ball'
target_element_id = 'goal'
element_to_drag = driver.find_element_by_id(element_to_drag_id)
target_element = driver.find_element_by_id(target_element_id)
ActionChains(driver).drag_and_drop(element_to_drag_id, target_element).perform()
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22. Get Page Source 

the_page_source = driver.page_source
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23. Get Cookies 

cookies_list = driver.get_cookies()
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24. Delete Cookies 

cookie_item = 'shopping_cart'
# delete one cookie
driver.delete_cookie(cookie_item)
# delete all cookies
driver.delete_all_cookies()
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25. Get first element from list 

the_id = 'register'
list_of_elements = driver.find_elements_by_id(the_id)
first_element = list_of_elements[0]
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26. Configure Page Load Timeout 

driver.set_page_load_timeout(20)
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27. Configure Element Load Timeout 

from selenium.webdriver.support.ui import WebDriverWait

the_id = 'register'
WebDriverWait(driver,10).until(EC.presence_of_element_located((By.ID, the_id)))
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28. Set window size 

driver.set_window_size(1600, 1200)
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29. Change the user agent string 

the_user_agent = 'hello'
chromedriver = 'C:/tests/chromedriver.exe'
options = webdriver.ChromeOptions()
options.add_argument('--user-agent = '+ the_user_agent)
driver = webdriver.Chrome(
   executable_path = chromedriver, 
   chrome_options = options)
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30. Simulate webcam and microphone 

chromedriver = 'C:/tests/chromedriver.exe'
options = webdriver.ChromeOptions()
options.add_argument("--use-fake-ui-for-media-stream")
options.add_argument("--use-fake-device-for-media-stream")
driver = webdriver.Chrome(
   executable_path = chromedriver, 
   chrome_options = options)
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31. Add Chrome Extension 

chromedriver = 'C:/tests/chromedriver.exe'
extension_path = 'C:/tests/my_extension.zip'
options = webdriver.ChromeOptions()
options.add_extension(extension_path)
driver = webdriver.Chrome(
   executable_path = chromedriver, 
   chrome_options = options)
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32. Emulate mobile device 

google_pixel_3_xl_user_agent = 'Mozilla/5.0 (Linux; Android 9.0; Pixel 3 XL Build/OPD3.170816.012) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.98 Mobile Safari/537.36'
pixel_3_xl_emulation = {
   "deviceMetrics": {
      "width": 411, 
      "height": 731, 
      "pixelRatio": 3
   },
   "userAgent": google_pixel_3_xl_user_agent
}
options = webdriver.ChromeOptions()
options.add_experimental_option("mobileEmulation", pixel_3_xl_emulation)
driver = webdriver.Chrome(
   executable_path = chromedriver, 
   chrome_options = options)
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I ♥️ Selenium, but I use Endtest instead.

It has so many features, such as:

  • Chrome extension to record your tests
  • Access to a cloud with real browsers on Windows and macOS machines
  • Access to real mobile devices
  • Detailed logs
  • Screenshot comparison
  • Live video of test executions
  • Video recording of test executions
  • Data-driven testing with CSV files
  • Scheduler
  • Automatic backups
  • Endtest API
  • Email notifications
  • Slack notifications
  • Webhook notifications
  • Endtest Mailbox
  • Different geolocations (🇺🇸🇩🇪🇬🇧🇫🇷🇦🇺🇯🇵)

And the Documentation section is a gold mine. 🤓

Top comments (6)

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ialexreis profile image
Alexandre Reis •

Pretty good article about selenium syntax and uses.

I used to build tests with selenium and JAVA, and instead of calling the elements id or xpath, I made a PageObject that stores every component used, removing the long id's from the action code.

I'm absolutely going to try endtest too.

Congratulations on your article!

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razgandeanu profile image
Klaus •

Thank you.
And it's great that you mentioned Page Object Model, it's really useful.
I forgot to mention it in this article.

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lmolivera profile image
Lucas Olivera •

What a quality post you have here, I really needed this!

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razgandeanu profile image
Klaus •

Thank you.

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mikaleb profile image
Mikaleb •

Question : why Selenium over something like TestCafe?

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meyy1180 profile image
Meyy1180 •

Great article , I must say.....
only one minor typo : element = driver.find_element_by_id(the_name)>>element = driver.find_element_by_name(the_name)

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